A Windows host and OS X clients will work fine. In regards to the data storage, if you're storing the images within the container field, you won't have to change anything at all. If you store the images by reference, the clients will need access to whatever folder they're being stored in.

To expand on that, each client should be set up to mount the shared folder with the same volumne name and file path. That mac specific file path is what would be entered into your container field's filepath line. That will happen automatially for newly inserted files. (And there are ways to use Replace field contents to make a mass update of these fields if you have relocated and/or renamed some portion of that file path.)